This invention relates to a new composition of matter, namely a pyromellitate fluorocarbon monomer containing up to 50 percent of its dimer. The new composition is useful in or on fiber to reduce soiling of fabric constructed of the fiber such as carpet, and will remain on fabric after normal wear and repeated washing.
It is known to use the monomer mixture of fluorocarbon meta and para pyromellitates in a yarn finish for nylon and polyester fiber for use in fabric, such as carpet, in U.S. Pat. No. 4,192,754 hereby incorporated by reference. This fluorocarbon is also disclosed in U.S. Pat. No. 4,209,610, hereby incorporated by reference. An improved process to manufacture this fluorocarbon pyromellitate is disclosed in U.S. Pat. No. 4,329,489, also hereby incorporated by reference.
It is suspected that the previously known fluorocarbon pyromellitate monomer inherently contained very small amounts (less than 1 percent) of dimer, considered impurities, which occurred naturally during its manufacture. However, a change in the manufacturing process by a supplier of the fluorocarbon pyromellitate produced a product which in use in finish on nylon fiber for carpets suddenly had different properties, discovered by the inventors. The inventors also analyzed the fluorocarbon pyromellitate and the yarn to discover its composition and the surprising properties of yarn having a finish containing the inventive composition.